JPH046360Y2 - - Google Patents

Description

[Detailed description of the invention] <<Field of the invention>> This invention relates to automobile interior parts such as door trims, and in particular to an automobile interior that reliably prevents migration of plasticizer from PVC resin used as a skin material. Regarding parts.

《Prior art and its problems》 As is well known, automotive interior parts such as door trims and instrument panels have a laminated structure in which a pad material that provides cushioning properties and a skin material that provides decorative properties are laminated on the surface of the core material. The body is used a lot.

When non-molded urethane foam (commonly known as slab urethane foam) is used as the above-mentioned pad material, the slab urethane foam has poor rigidity, so the shape especially at the corners becomes unclear and the three-dimensional effect cannot be emphasized. First, a decline in design quality was inevitable.

For this reason, molded urethane foam is used only in areas that are particularly easy to touch by passengers or where it is desired to create a three-dimensional effect.By selectively using molded urethane foam in this way, functionality is improved. Recently, there has been a trend towards designs that take this into account.

When the molded urethane foam mentioned above is used as a pad material, it has the disadvantage of being heavier than the slab urethane foam, but on the other hand, the molded urethane foam has strong rigidity and can accurately form corner shapes, making it especially sharp and high. It is a suitable material for emphasizing three-dimensional shapes because it can express light lines, and it also has advantages that more than compensate for its weight, such as the ability to provide a cushioning effect when an impact is applied.

However, when this type of molded urethane foam was used as a pad material, there was one problem.

That is, when a PVC resin sheet or a resin sheet containing PVC resin is used as the skin material that covers the surface of this type of molded urethane foam,
This means that the plasticizer in these skin materials easily migrates to the molded urethane foam side. One possible reason for this is that the surface skin layer of the molded urethane foam is dense and the contact area with the skin material is larger than that of the slab urethane foam.

By the way, PVC resin is often used as a skin material for automobile interior parts because it is easy to perform various molding processes and the material cost is low, but as mentioned above, the migration of plasticizers in PVC resin Due to this problem, the amount of residual plasticizer in the PVC resin sheet decreases due to changes over time, and as a result,
The PVC resin sheet hardens and deteriorates, which in turn causes cracks to appear on the product surface, resulting in poor aesthetics and a product with an extremely poor feel to the touch.

Therefore, a thin slab urethane foam sheet is interposed on the surface of the molded urethane foam.
Attempts have been made to prevent the plasticizer from migrating into the molded urethane foam, but this method requires an additional step to set the slab urethane foam sheet, which increases costs and reduces the amount of plasticizer transferred into the molded urethane foam. It has been pointed out that this slab urethane foam hinders the creation of clear shapes.

It has also been proposed to coat the back side of the PVC resin sheet with polyamide resin to prevent the plasticizer in the PVC resin sheet from migrating to the molded urethane foam, but the barrier effect of this polyamide resin cannot be expected to be that great. However, it did not reliably prevent plasticizer migration.

《Purpose of the invention》 This invention was made in view of the above-mentioned circumstances, and its purpose is to use a PVC resin sheet or a resin sheet containing PVC resin as a skin material, and to use a rigid material as a pad material. In automotive interior parts that use molded urethane foam at least in part, it reliably prevents the plasticizer in the PVC resin from migrating into the pad material and maintains the flexibility of the skin material over a long period of time. The purpose of the present invention is to provide an interior part for an automobile that does not deteriorate the aesthetic appearance of the product and maintains a sufficient buffering function.

<<Structure and effect of the invention>> In order to achieve the above object, the present invention laminates pad materials on the surface of the core material, and further layers the outer periphery of the pad materials.
In automobile interior parts covered with a skin material made of a PVC resin sheet or a resin sheet partially containing PVC resin, a part of the pad material is molded with molded urethane having excellent rigidity and a desired curved surface shape. The molded urethane foam is formed of a foam, and at least one of the joint surfaces of the molded urethane foam and the skin material is formed as a finely uneven surface.

In other words, this invention uses PVC resin sheet or
An automobile interior part that uses a resin sheet containing PVC resin and a molded urethane foam body as a thickened pad material from the viewpoint of design and cushioning properties, wherein at the joint between the pad material and the skin material, Since it has minute irregularities formed on at least one of the bonding surfaces, the contact area between the pad material and the skin material is greatly reduced, and a fine air layer is interposed between the two. It is possible to reliably prevent the plasticizer in the PVC resin from migrating into the pad material.

Therefore, the amount of plasticizer in the PVC resin can be kept constant, so it will not change over time.
PVC resin hardens and does not deteriorate, preventing the occurrence of cracks on the product surface, keeping the skin material, that is, the product surface, in good condition at all times, preventing deterioration in appearance, and its cushioning function (touchability). It has various effects such as being able to maintain a good feeling for a long period of time.

<<Description of Embodiment>> Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a partially cutaway perspective view of an automobile door trim showing a first embodiment of the present invention, Fig. 2 is an explanatory diagram of assembly of the same automobile door trim, and Fig. 3 shows a second embodiment of the invention. FIG. 4 is a partially cutaway perspective view of the automobile door trim shown in FIG. 4, which is a graph showing the elongation rate of the resin sheet after a heat aging test, showing experimental data comparing resins of a conventional example and an example of the present invention.

Reference numeral 1 in the figure indicates an automobile door trim, and this door trim 1 has a core material 2 made of a composite resin board or the like.
, a slab urethane foam 3 laminated on a relatively flat portion of the surface of the core material 2, and a molded urethane foam 4 laminated on the thickened portion 2a of the core material 2.
and a PVC resin sheet 5 covering their outer peripheries.

The molded urethane foam 4, which is relatively heavy, is used only in areas that require a three-dimensional shape or are easily touched by passengers' hands, and the other areas are covered with lightweight, thin slab urethane foam 3.
is used, the weight of the entire product can be reduced, and a clear shape can be formed using the molded urethane foam 4, resulting in a product with excellent design.

Furthermore, a fine uneven surface 4a is formed on the surface of the molded urethane foam 4 by, for example, matte finishing, graining, etc., so that the contact area between the surface of the molded urethane foam 4 and the PVC resin sheet 5 is small. In addition, since a fine air layer is interposed between the two, the plasticizer in the PVC resin is prevented from migrating to the molded urethane foam 4 side due to changes over time.

Next, the production of the door trim 1 will be explained.

First, the core material 2 is made by extruding a mixture of polypropylene resin and wood flour filler into a sheet using a T-die extrusion molding machine, and then heating and softening this sheet. molded into a shape that roughly matches the shape of the product. This molded core material 2 is placed on a mounting table 6, and after applying adhesive to the surface 2a of the core material 2, a slab urethane foam 3 and a molded urethane foam 4 are bonded onto the surface 2a of the core material 2. let Then, a PVC resin sheet 5 heated and softened by a heating device (not shown) is coated and integrated from above by a vacuum bonding process, and the outer peripheral end of the PVC resin sheet 5 is attached to the core material 2.
The production of the door trim 1 is completed by folding it back and fixing it to the back side.

At this time, the molded urethane foam 4 is molded into the desired shape using a mold (not shown), and a skin texture pattern is engraved on the inner wall surface of the mold.
Therefore, a finely uneven surface 4a is formed on the surface of the molded urethane foam 4.

The finely uneven surface 4a formed on the molded urethane foam 4 may be formed using sandblasting or the like after the molded urethane foam 4 is molded.

Next, a second embodiment of the automobile door trim according to the present invention will be described based on FIG.

Note that the same parts as in the first embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the skin material used is one in which the back surface of the PVC resin sheet 7 is coated with a polyamide resin 8, and the surface of this polyamide resin is further subjected to a satin finish.

Therefore, between the molded urethane foam 4 and the skin material, a fine uneven surface 8a is formed on the back side of the skin material, so as in the first embodiment, the plasticizer in the PVC resin sheet 7 is mixed with molded urethane. There is no transition to the form 4 side.

In manufacturing the above skin material, the PVC resin sheet 7 is extruded using a calendar molding machine, and at the same time, a polyamide resin 8 is coated on one side of the sheet by gravure coating, and a matte roller (not shown) or the like is applied to the polyamide resin 8 side. A satin finish is applied.

Next, the effects of the present invention will be explained based on the following experimental examples.

First, create samples 1 to 4 in the following manner.

Sample 1: A molded urethane foam (vertical dimension x horizontal dimension x thickness = 120 mm x 150 mm x 8 mm) was molded and wrapped around the outer circumference of a cylindrical body with a diameter of 50 mm, and a PVC resin sheet (sheet thickness 0.35 mm) was placed on top of it. Cover and fix.

Sample 2: Same as Sample 1, but the surface of the molded urethane foam was textured.

Sample 3: Same as sample 1, but with PVC
Instead of a resin sheet, PVC is coated with polyamide resin with a satin finish on the back side.
One that uses a resin sheet.

Sample 4: Same as sample 2, but with PVC
Instead of a resin sheet, it uses a PVC resin sheet coated with polyamide resin with a satin finish on the back side.

Samples 1 to 4 are then subjected to a heat aging test.

Test conditions: 110°C x 100 hours 110°C x 200 hours 110°C x 300 hours After conducting heat aging tests under each of the above conditions, PVC resin sheets of samples 1 and 2 and polyamide resin coatings of samples 3 and 4 were coated.
The PVC resin sheet was taken out and the elongation rate was measured.

The graph shown in Figure 4 shows the elongation rate of the resin sheets of Samples 1 to 4 after each heat aging test.
As is clear from the graph in Figure 4, sample 1
It can be seen that the elongation rate of the (conventional product) PVC resin sheet rapidly decreases in a short heat aging test.
In addition, the resin sheet tested for sample 2 showed a 250% elongation rate even when the heat aging test time was 100 hours, which is in good contrast to sample 1, which showed almost no elongation rate after 100 hours. be.

Similarly, the resin sheet in Sample 3 also shows the same curve as Sample 2.

This indicates that the same effect can be obtained by forming a finely uneven surface on the surface of the molded urethane foam, or by forming a finely uneven surface on the bonding surface of the resin sheet.

Furthermore, sample 4 is a combination of sample 2 and sample 3, and as is clear from this graph, even after 200 hours of heat aging test time, the elongation rate is nearly 200%. As is clear from this, it can be seen that even more effects can be obtained if finely uneven surfaces are formed on both the surface of the molded urethane foam and the surface of the resin sheet.

In this way, by forming the molded urethane foam on the front side and forming a finely uneven surface on the back side of the PVC resin sheet, or at least on one side thereof, it is possible to reliably prevent plasticizer migration from the PVC resin side. Various negative effects caused by plasticizer migration can be eliminated.

In the above embodiment, a PVC resin sheet was used as the skin material, but it goes without saying that a resin sheet in which PVC resin is mixed with ABS resin may be used as the skin material.

Further, embodiments of the present invention are not limited to door trims, but may be applied to general automobile interior parts such as instrument panels, and thus the present invention has an extremely wide range of application.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of an automobile door trim showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of assembly of the automobile door trim, and Fig. 3 is a second embodiment of the invention.
FIG. 4, a cutaway perspective view showing an example of an automobile door trim, is for explaining the operation of the present invention.
It is a graph showing the elongation rate change of the resin sheet after a heat aging test. 1... Automobile door trim, 2... Core material, 3...
... Slab urethane foam, 4... Mold urethane foam, 4a, 8a... Uneven surface, 5, 7...
...PVC resin sheet, 6... Mounting table, 8... Polyamide resin.

Claims (1)

[Scope of claim for utility model registration] Automotive interior parts made by laminating pad materials on the surface of a core material, and further covering the outer periphery with a skin material made of a PVC resin sheet or a resin sheet partially containing PVC resin. A part of the pad material is made of a molded urethane foam having excellent rigidity and a desired curved surface shape, and at least one of the joint surfaces of the molded urethane foam and the skin material is formed of a molded urethane foam having a desired curved shape. An automobile interior part characterized by being formed as a finely uneven surface.